Aleph 1.2 Service Manual
Rev 0 9/20/96
Aleph 1.2 Service Manual.
The Aleph 1.2 is a monoblock 200 watt audio power amplifier which operates in single-
ended class A mode.
The Aleph 1.2 has only two gain stages which are biased by current sources. Because
of the inherent simplicity of the circuit, it is easy to understand and repair. There are no
Figure 1 shows the simplified schematic of the amplifier. Two p channel Mosfets form
an input differential pair biased by a current source operating at about 20 ma. The
drain of the input Mosfet is attached to the gate of an n channel power Mosfet which
forms the active output stage. It is biased by a current source at 4 amps.
The voltage rails of the supply are at 60 volts, and each channel draws approximately
Figure 2 shows the actual schematic for the amplifier.
F1 is a slow blow fuse|